Refrigeration cycle apparatus

Abstract

This refrigeration cycle apparatus comprises: a heat source unit that constitutes at least a portion of a refrigerant circuit; a load unit that is connected to the heat source unit; and a control device that controls the heat source unit. The control device includes: an information acquisition unit that acquires the type of refrigerant used in the refrigerant circuit; a connection determination unit that determines whether a safety device is connected when the type of refrigerant acquired by the information acquisition unit is not a non-flammable refrigerant; and an interlock unit that prohibits the operation of the heat source unit when it is determined by the connection determination unit that the safety device is not connected.

Description

Refrigeration cycle equipment

[0001] The present disclosure relates to a refrigeration cycle device.

[0002] Conventionally, in refrigeration cycle devices equipped with a refrigerant circuit, it is known to provide safety measures against refrigerant leakage due to piping damage, etc. For example, Patent Document 1 discloses an air conditioner equipped with a refrigerant sensor that detects refrigerant leakage, an alarm device that notifies of refrigerant leakage, and a shutoff valve that shuts off the flow of refrigerant, as safety devices in the event of refrigerant leakage.

[0003] JP 2019-52785 A

[0004] Refrigerants with different flammability, such as non-flammable, slightly flammable, or flammable refrigerants, are used in the refrigeration cycle device's refrigeration circuit. If a refrigeration cycle device is designed to use a non-flammable refrigerant and safety devices such as a refrigerant sensor and a shut-off valve are not installed, and a slightly flammable or flammable refrigerant is accidentally introduced into the refrigerant circuit, it will be impossible to detect and take measures against the refrigerant leak, resulting in a decrease in safety.

[0005] The present disclosure is intended to solve the above-mentioned problems and aims to ensure safety in the event of a refrigerant leak in a refrigeration cycle device.

[0006] The refrigeration cycle device of the present disclosure comprises a heat source unit that constitutes at least a part of a refrigerant circuit, a load unit connected to the heat source unit, and a control device that controls the heat source unit, and the control device has an information acquisition unit that acquires the type of refrigerant used in the refrigerant circuit, a connection determination unit that determines whether a safety device is connected if the type of refrigerant acquired by the information acquisition unit is not a non-flammable refrigerant, and an interlock unit that prohibits operation of the heat source unit if the connection determination unit determines that the safety device is not connected.

[0007] According to the refrigeration cycle device of the present disclosure, if it is determined that the safety device is not connected, the device has an interlock section that prohibits operation of the heat source unit, thereby ensuring safety in the event of a refrigerant leak in the refrigeration cycle device.

[0008] FIG. 1 is a schematic configuration diagram of a refrigeration cycle device according to embodiment 1. FIG. 2 is a control block diagram of a control device according to embodiment 1. FIG. 3 is a flowchart showing the flow of interlock processing in embodiment 1. FIG. 4 is a schematic configuration diagram of a refrigeration cycle device according to embodiment 2. FIG. 5 is a control block diagram of a control device according to embodiment 2. FIG. 6 is a flowchart showing the flow of interlock processing in embodiment 2. FIG. 7 is a flowchart showing the flow of interlock processing in embodiment 3. FIG. 8 is a control block diagram of a control device according to embodiment 4. FIG. 9 is a flowchart showing the flow of interlock processing in embodiment 4. FIG. 10 is a control block diagram of a control device according to embodiment 5. FIG. 11 is a flowchart showing the flow of interlock processing in embodiment 5.

[0009] Hereinafter, embodiments of a design device and a design method according to the present disclosure will be described with reference to the drawings. In each drawing, components denoted by the same reference numerals are identical or equivalent components, and this is common throughout the specification. Note that in each drawing, the relative dimensional relationships or shapes of each component may differ from those in reality.

[0010] Embodiment 1. Figure 1 is a schematic diagram of a refrigeration cycle apparatus 100 according to embodiment 1. The refrigeration cycle apparatus 100 may be a direct expansion air conditioner that conditions a room, a heat pump chiller that conditions air using chilled or hot water, a dedicated cooling unit that does not have a cooling / heating switchable unit, or a refrigerator for cooling a refrigerated warehouse. As shown in Figure 1, the refrigeration cycle apparatus 100 includes a heat source unit 1, a load unit 2, and a control device 3. The refrigeration cycle apparatus 100 also includes a safety device 4 that serves as a safety measure in the event of a refrigerant leak, depending on the type of refrigerant used.

[0011] The heat source unit 1 is, for example, an outdoor unit of an air conditioner installed outdoors. The heat source unit 1 includes a compressor, a four-way valve, an outdoor heat exchanger that exchanges heat between air and a refrigerant, an outdoor fan that sends air to the outdoor heat exchanger, and a pressure reducing valve. The load unit 2 is, for example, an indoor unit of an air conditioner installed in a space to be air-conditioned. The load unit 2 includes an indoor heat exchanger that exchanges heat between air and a refrigerant, and a fan that sends air to the indoor heat exchanger.

[0012] The heat source unit 1 and the load unit 2 are connected by piping 10. A refrigerant circuit is formed by connecting the compressor, four-way valve, outdoor heat exchanger, and pressure reducing valve of the heat source unit 1 and the indoor heat exchanger of the load unit 2 by piping. The refrigeration cycle apparatus 100 of this embodiment can use multiple types of refrigerants, including non-flammable refrigerants such as R410A, slightly flammable refrigerants such as R32 or HFO1234ze, and flammable refrigerants (highly flammable refrigerants) such as R290, as the refrigerant that flows through the refrigerant circuit.

[0013] The control device 3 is composed of a computer including a memory for storing data and programs required for control and a processor such as a CPU for executing the programs, a dedicated processing circuit such as an ASIC or FPGA, or both. Note that in Fig. 1, the control device 3 is provided separately from the heat source unit 1 and the load unit 2, but the control device 3 may be provided in either the heat source unit 1 or the load unit 2, or the heat source unit 1 and the load unit 2 may each be provided with the control device 3.

[0014] The control device 3 is connected to the heat source unit 1 and the safety device 4 via wired or wireless communication and controls the operation of the heat source unit 1 depending on the connection status of the safety device 4. The safety device 4 is at least one of a refrigerant leak detection device 41, a shutoff valve 42, an alarm device 43, and a ventilation device 44. The safety device 4 connected varies depending on the type of refrigeration cycle apparatus 100. For example, if the refrigeration cycle apparatus 100 is a direct expansion air conditioner, a refrigerant flows to the load unit 2, and therefore at least one of the refrigerant leak detection device 41, the shutoff valve 42, the alarm device 43, and the ventilation device 44 is connected as the safety device 4. Furthermore, if the refrigeration cycle apparatus 100 is a heat pump chiller or a refrigerator and no refrigerant flows to the load unit 2, the shutoff valve 42 is unnecessary, and at least one of the refrigerant leak detection device 41, the alarm device 43, and the ventilation device 44 is connected as the safety device 4. Furthermore, the ventilation device 44 is not essential as the safety device 4 and may be omitted. Furthermore, a plurality of refrigerant leakage detection devices 41, alarm devices 43, and ventilation devices 44 may be provided.

[0015] The refrigerant leak detection device 41 is disposed, for example, near the indoor heat exchanger in the load unit 2. The refrigerant leak detection device 41 has a gas sensor that measures the concentration of refrigerant in the air, detects the same or equivalent gas as the refrigerant used in the refrigerant circuit of the refrigeration cycle apparatus 100, and determines the presence or absence of a refrigerant leak based on the detection result. The refrigerant leak detection device 41 may be provided on the heat source unit 1, the piping 10 connecting the heat source unit 1 and the load unit 2, or the floor or wall of the room in which the load unit 2 is installed.

[0016] The shutoff valve 42 is a solenoid valve that is provided in the pipe 10 connecting the heat source unit 1 and the load unit 2 and whose opening and closing is controlled. The shutoff valve 42 closes when the refrigerant leak detection device 41 detects a refrigerant leak, and by closing the pipe 10, the flow of refrigerant to the load unit 2 is cut off.

[0017] The alarm device 43 is a speaker that emits an alarm sound when a refrigerant leak is detected by the refrigerant leak detection device 41. Alternatively, the alarm device 43 may be a display device that displays a warning message when a refrigerant leak is detected by the refrigerant leak detection device 41.

[0018] The ventilation device 44 is provided on a wall of the room in which the load unit 2 is installed, etc. The ventilation device 44 has a ventilation fan, and when the refrigerant leak detection device 41 detects a refrigerant leak, the ventilation fan is rotated to exhaust the air in the room in which the load unit 2 is installed to the outdoors.

[0019] 2 is a control block diagram of the control device 3 according to the first embodiment. As shown in FIG. 2, the control device 3 includes an information acquisition unit 31, a flammability determination unit 32, a connection determination unit 33, an interlock unit 34, and a notification unit 35. The information acquisition unit 31, the flammability determination unit 32, the connection determination unit 33, the interlock unit 34, and the notification unit 35 are functional units implemented by a processor, such as a CPU, that configures the control device 3, executing a program. Alternatively, at least one of the information acquisition unit 31, the flammability determination unit 32, the connection determination unit 33, the interlock unit 34, and the notification unit 35 may be implemented by a processing circuit, such as an ASIC or an FPGA.

[0020] The information acquisition unit 31 acquires the type of refrigerant used in the refrigeration cycle apparatus 100. The type of refrigerant used in the refrigeration cycle apparatus 100 is input by the user using an external device such as a remote controller of the refrigeration cycle apparatus 100 or a smartphone carried by the user, or an input device connected to the control device 3. The information acquisition unit 31 communicates with the external device or the input device to acquire the type of refrigerant input by the user.

[0021] The flammability determination unit 32 determines whether the refrigerant used in the refrigeration cycle device 100 is a non-flammable refrigerant, a slightly flammable refrigerant, or a flammable refrigerant, based on the type of refrigerant acquired by the information acquisition unit 31.

[0022] When the flammability determination unit 32 determines that the refrigerant used in the refrigeration cycle apparatus 100 is not a non-flammable refrigerant, the connection determination unit 33 determines whether the safety device 4 is connected to the control device 3. For example, when the control device 3 and the safety device 4 are configured to communicate wirelessly, the connection determination unit 33 transmits a connection establishment request to the safety device 4. Then, when the connection determination unit 33 receives a response from the safety device 4 within a predetermined response period after transmitting the connection establishment request, the connection determination unit 33 determines that the safety device 4 is connected. On the other hand, when the connection determination unit 33 does not receive a response from the safety device 4 within the response period after transmitting the connection establishment request, the connection determination unit 33 determines that the safety device 4 is not connected. Furthermore, when the control device 3 and the safety device 4 are configured to communicate via wire, or when the control device 3 and the safety device 4 are configured to be wired and connected by interlock wiring or the like, the connection determination unit 33 may detect whether the wiring connector is physically connected and determine whether the safety device 4 is connected based on the detection result.

[0023] Furthermore, among the safety devices 4, the refrigerant leak detection device 41, the shutoff valve 42, the alarm device 43, and the ventilation device 44, which devices should be connected vary depending on the type and installation environment of the refrigeration cycle apparatus 100. The connection determination unit 33 determines that the safety device 4 is connected when a device that should be connected is connected among the safety devices 4. The device that should be connected is determined based on the laws and regulations of the country and building in which the refrigeration cycle apparatus 100 is installed, the type of refrigerant used, the amount of refrigerant sealed in the refrigerant circuit, the size of the space in which the heat source unit 1 or the load unit 2 is installed, and the like. Specifically, the connection determination unit 33 may determine that the safety device 4 is connected when all of the refrigerant leak detection device 41, the shutoff valve 42, the alarm device 43, and the ventilation device 44 are connected, or may determine that the safety device 4 is connected when at least one of the refrigerant leak detection device 41, the shutoff valve 42, the alarm device 43, and the ventilation device 44 is connected and the remaining devices are not connected. The determination criteria of the connection determination unit 33 may be set in advance or may be set by the user.

[0024] The interlock unit 34 controls the operation of the heat source unit 1 according to the determination result of the connection determination unit 33 regarding the connection of the safety device 4. Specifically, the interlock unit 34 permits operation of the heat source unit 1 when the connection determination unit 33 determines that the safety device 4 is connected, and prohibits operation of the heat source unit 1 when the connection determination unit 33 determines that the safety device 4 is not connected. When operation of the heat source unit 1 is prohibited by the interlock unit 34, the compressor is not started. As a result, refrigerant does not circulate in the refrigerant circuit. In the following description, prohibiting operation of the heat source unit 1 may also be referred to as "interlock."

[0025] When the connection determination unit 33 determines that the safety device 4 is not connected, the notification unit 35 issues an alarm or a warning message to notify that the safety device 4 is not connected. Specifically, the notification unit 35 causes the remote controller of the refrigeration cycle apparatus 100, the alarm device 43, or a speaker or display device connected to the control device 3 to output an alarm indicating that the safety device 4 is not connected or display a warning message.

[0026] Next, a process at the start of operation of the refrigeration cycle apparatus 100 of this embodiment will be described. In this embodiment, an interlock process is performed at the start of operation of the refrigeration cycle apparatus 100 to check safety measures in case of refrigerant leakage. Figure 3 is a flowchart showing the flow of the interlock process in embodiment 1. In this process, first, the information acquisition unit 31 acquires the type of refrigerant used in the refrigeration cycle apparatus 100 (S1).

[0027] Then, the flammability determination unit 32 determines whether the refrigerant used is a non-flammable refrigerant (S2). If the refrigerant used is a non-flammable refrigerant (S2: YES), the interlock unit 34 permits operation of the heat source unit 1 (S3). If the refrigerant used is a non-flammable refrigerant, no accidents such as fires will occur even if a refrigerant leak occurs. Therefore, in the case of a non-flammable refrigerant, the refrigeration cycle apparatus 100 can be operated even if the safety device 4 is not connected.

[0028] On the other hand, if the refrigerant used is not a non-flammable refrigerant, i.e., if the refrigerant used is a slightly flammable refrigerant or a flammable refrigerant (S2: NO), the connection determination unit 33 determines whether the safety device 4 is connected to the control device 3 (S4). If the safety device 4 is connected to the control device 3 (S4: YES), the interlock unit 34 permits operation of the heat source unit 1 (S3). In this case, safety measures have been provided in case of leakage of a slightly flammable refrigerant or a flammable refrigerant, so the refrigeration cycle apparatus 100 can be operated.

[0029] On the other hand, if the safety device 4 is not connected (S4: NO), the interlock unit 34 prohibits operation of the heat source unit 1 (S5). Then, the notification unit 35 notifies that the safety device 4 is not connected (S6). Thereafter, the process returns to step S4, and operation of the heat source unit 1 is prohibited until the safety device 4 is connected.

[0030] As described above, according to this embodiment, when a slightly flammable or flammable refrigerant is used and the safety device 4 is not connected to the refrigeration cycle apparatus 100, operation of the heat source unit 1 is prohibited. That is, if the input refrigerant type information does not match the configuration of the refrigeration cycle apparatus 100, an interlock is performed. As a result, if a slightly flammable or flammable refrigerant is mistakenly charged when the safety device 4 is not connected, the heat source unit 1 will not operate, preventing refrigerant leakage and improving safety.

[0031] Embodiment 2. Embodiment 2 will be described. A refrigeration cycle apparatus 100A of Embodiment 2 differs from Embodiment 1 in that it includes a plurality of load units 2 and in the content of the interlock process. FIG. 4 is a schematic configuration diagram of the refrigeration cycle apparatus 100A according to Embodiment 2. As shown in FIG. 4, the refrigeration cycle apparatus 100A includes a heat source unit 1, a first load unit 2A, a second load unit 2B, and a control device 3A. The first load unit 2A and the second load unit 2B are connected in parallel to the heat source unit 1. The refrigeration cycle apparatus 100A also includes a first safety device 4A and a second safety device 4B, which serve as safety measures in the event of refrigerant leakage, depending on the type of refrigerant used.

[0032] The configuration and functions of the heat source unit 1 are the same as those in embodiment 1. The first load unit 2A is, for example, an indoor unit of an air conditioner installed in the first space R1. The second load unit 2B is, for example, an indoor unit of an air conditioner installed in the second space R2. The first load unit 2A and the second load unit 2B each include an indoor heat exchanger that exchanges heat between air and a refrigerant, and a fan that sends air to the indoor heat exchanger.

[0033] The heat source unit 1 and the first load unit 2A are connected by a first pipe 10A. The heat source unit 1 and the second load unit 2B are connected by a second pipe 10B. A refrigerant circuit is formed by connecting the compressor, four-way valve, outdoor heat exchanger, and pressure reducing valve of the heat source unit 1 and the indoor heat exchangers of the first load unit 2A and the second load unit 2B by pipes. The refrigeration cycle apparatus 100A of this embodiment can use multiple types of refrigerants, including non-flammable refrigerants such as R410A, mildly flammable refrigerants such as R32 or HFO1234ze, and flammable refrigerants (highly flammable refrigerants) such as R290, as the refrigerant that flows through the refrigerant circuit.

[0034] The configuration of the control device 3A is the same as the control device 3 in embodiment 1. The control device 3A is connected to the heat source unit 1, the first safety device 4A, and the second safety device 4B so as to be able to communicate with them via wired or wireless communication, and controls the operation of the heat source unit 1 and the opening and closing of the first shutoff valve 42A and the second shutoff valve 42B depending on the connection status of the first safety device 4A and the second safety device 4B. The first safety device 4A is a safety device corresponding to the first load unit 2A and is installed in the first space R1. The first safety device 4A is at least one of the first refrigerant leak detection device 41A, the first shutoff valve 42A, the first alarm device 43A, and the first ventilation device 44A. The second safety device 4B is a safety device corresponding to the second load unit 2B and is installed in the second space R2. The second safety device 4B is at least one of the second refrigerant leak detection device 41B, the second shutoff valve 42B, the second alarm device 43B, and the second ventilation device 44B. As in the first embodiment, the safety devices to be connected vary depending on the type of the refrigeration cycle apparatus 100A.

[0035] The first refrigerant leak detection device 41A is disposed, for example, near the indoor heat exchanger in the first load unit 2A. The first refrigerant leak detection device 41A has a gas sensor that measures the concentration of refrigerant in the air, detects the same or equivalent gas as the refrigerant used in the refrigeration cycle apparatus 100A, and determines whether or not a refrigerant leak has occurred based on the detection result. The first refrigerant leak detection device 41A may be provided on the heat source unit 1, the first piping 10A connecting the heat source unit 1 and the first load unit 2A, or the floor or wall of the room in which the first load unit 2A is installed.

[0036] The second refrigerant leak detection device 41B is disposed, for example, near the indoor heat exchanger in the second load unit 2B. The second refrigerant leak detection device 41B has a gas sensor that measures the concentration of refrigerant in the air, detects the same or equivalent gas as the refrigerant used in the refrigeration cycle apparatus 100A, and determines whether or not a refrigerant leak has occurred based on the detection result. The second refrigerant leak detection device 41B may be provided on the heat source unit 1, the second piping 10B connecting the heat source unit 1 and the second load unit 2B, or the floor or wall of the room in which the second load unit 2B is installed.

[0037] The first shutoff valve 42A is a solenoid valve that is provided in the first piping 10A connecting the heat source unit 1 and the first load unit 2A and whose opening and closing is controlled. The first shutoff valve 42A closes when the first refrigerant leak detection device 41A detects a refrigerant leak, and by closing the first piping 10A, it cuts off the flow of refrigerant to the first load unit 2A.

[0038] The second shutoff valve 42B is a solenoid valve that is provided in the second piping 10B that connects the heat source unit 1 and the second load unit 2B and whose opening and closing is controlled. The second shutoff valve 42B closes when the second refrigerant leak detection device 41B detects a refrigerant leak, and by closing the second piping 10B, the flow of refrigerant to the second load unit 2B is cut off.

[0039] The first alarm device 43A is a speaker that emits an alarm sound when a refrigerant leak is detected by the first refrigerant leak detection device 41A, or may be a display device that displays a warning message when a refrigerant leak is detected by the first refrigerant leak detection device 41A.

[0040] The second alarm device 43B is a speaker that emits an alarm sound when a refrigerant leak is detected by the second refrigerant leak detection device 41B, or may be a display device that displays a warning message when a refrigerant leak is detected by the second refrigerant leak detection device 41B.

[0041] The first ventilation device 44A is provided on a wall of the first space R1 in which the first load unit 2A is installed, etc. The first ventilation device 44A has a ventilation fan, and when the first refrigerant leak detection device 41A detects a refrigerant leak, the ventilation fan is rotated to exhaust air from the first space R1 to the outdoors.

[0042] The second ventilation device 44B is provided on a wall of the second space R2 in which the second load unit 2B is installed, etc. The second ventilation device 44B has a ventilation fan, and when the second refrigerant leak detection device 41B detects a refrigerant leak, the second ventilation device 44B rotates the ventilation fan to exhaust air from the second space R2 to the outdoors.

[0043] Fig. 5 is a control block diagram of a control device 3A according to embodiment 2. As shown in Fig. 5, the control device 3A has an information acquisition unit 31, a flammability determination unit 32, a connection determination unit 33, an interlock unit 34, a notification unit 35, and a shutoff valve control unit 36. The configurations and functions of the information acquisition unit 31 and the flammability determination unit 32, as well as the configurations of the connection determination unit 33, the interlock unit 34, and the notification unit 35, are the same as those in embodiment 1.

[0044] When the flammability determination unit 32 determines that the refrigerant used in the refrigeration cycle apparatus 100 is not a non-flammable refrigerant, the connection determination unit 33 determines whether the first safety device 4A and the second safety device 4B are connected or not. The determination method and criteria used by the connection determination unit 33 are the same as those in the first embodiment.

[0045] The interlock unit 34 controls the operation of the heat source unit 1 depending on the connection status of the first safety device 4A and the second safety device 4B determined by the connection determination unit 33. Specifically, the interlock unit 34 permits operation of the heat source unit 1 when the connection determination unit 33 determines that at least one of the first safety device 4A and the second safety device 4B is connected, and prohibits operation of the heat source unit 1 when the connection determination unit 33 determines that both the first safety device 4A and the second safety device 4B are not connected.

[0046] When it is determined that at least one of the first safety device 4A and the second safety device 4B is not connected, the notification unit 35 issues an alarm or a warning message to notify that the device is not connected.

[0047] The shutoff valve control unit 36 ​​is a functional unit realized by a processor such as a CPU constituting the control device 3A executing a program, or by a processing circuit such as an ASIC or FPGA. The shutoff valve control unit 36 ​​controls the opening and closing of the first shutoff valve 42A and the second shutoff valve 42B depending on the connection status of the first safety device 4A and the second safety device 4B determined by the connection determination unit 33. Specifically, when the connection determination unit 33 determines that the first safety device 4A is not connected, the shutoff valve control unit 36 ​​closes the first shutoff valve 42A and closes the first piping 10A to shut off the flow of refrigerant to the first load unit 2A. When the connection determination unit 33 determines that the second safety device 4B is not connected, the shutoff valve control unit 36 ​​closes the second shutoff valve 42B and closes the second piping 10B to shut off the flow of refrigerant to the second load unit 2B.

[0048] 6 is a flowchart showing the flow of the interlock process in the second embodiment. In this process, the information acquisition unit 31 first acquires the type of refrigerant used in the refrigeration cycle apparatus 100 (S21). Then, the flammability determination unit 32 determines whether the refrigerant used is a non-flammable refrigerant (S22). If the refrigerant used is a non-flammable refrigerant (S22: YES), the interlock unit 34 permits operation of the heat source unit 1 (S23). If the refrigerant used is a non-flammable refrigerant, an accident such as a fire will not occur even if a refrigerant leak occurs. Therefore, if the refrigerant used is a non-flammable refrigerant, the refrigeration cycle apparatus 100A can be operated even if the first safety device 4A and the second safety device 4B are not connected.

[0049] On the other hand, if the refrigerant used is not a non-flammable refrigerant, i.e., if the refrigerant used is a slightly flammable refrigerant or a flammable refrigerant (S22: NO), the connection determination unit 33 determines whether the first safety device 4A and the second safety device 4B are connected to the control device 3A (S24). If both the first safety device 4A and the second safety device 4B are connected (S24: both connected), the interlock unit 34 permits operation of the heat source unit 1 (S23). In this case, safety measures are provided in case of leakage of a slightly flammable refrigerant or a flammable refrigerant, and the refrigeration cycle apparatus 100A can be operated.

[0050] Furthermore, if only the first safety device 4A is connected and the second safety device 4B is not connected (S24: only the first safety device is connected), the shutoff valve control unit 36 ​​closes the second shutoff valve 42B, and the interlock unit 34 permits operation of the heat source unit 1 (S25). Then, the notification unit 35 notifies that the second safety device 4B is not connected (S28). This allows only the first load unit 2A, to which a safety device is connected, to operate.

[0051] Furthermore, if only the second safety device 4B is connected and the first safety device 4A is not connected (S24: only the second safety device is connected), the shutoff valve control unit 36 ​​closes the first shutoff valve 42A, and the interlock unit 34 permits operation of the heat source unit 1 (S26). Then, the notification unit 35 notifies that the first safety device 4A is not connected (S28). This allows only the second load unit 2B, to which a safety device is connected, to operate.

[0052] Furthermore, if both the first safety device 4A and the second safety device 4B are not connected (S24: both not connected), the interlock unit 34 prohibits operation of the heat source unit 1 (S27). Then, the notification unit 35 notifies that both the first safety device 4A and the second safety device 4B are not connected (S28). After the notification by the notification unit 35, the process returns to step S24, and operation of the heat source unit 1 is prohibited until at least one of the first safety device 4A and the second safety device 4B is connected.

[0053] As described above, according to this embodiment, if a slightly flammable or flammable refrigerant is mistakenly charged when the safety device 4 is not connected, the heat source unit 1 is not operated, thereby preventing refrigerant leakage and improving safety, as in the case of embodiment 1. Furthermore, if the refrigeration cycle apparatus 100A has multiple systems, the effects of operational restrictions on the heat source unit 1 can be minimized by operating only the system to which the safety device is connected.

[0054] 4, the refrigeration cycle apparatus 100A is configured to include two load units, but may include three or more load units. Also, the refrigeration cycle apparatus 100A may include a plurality of heat source units 1.

[0055] Furthermore, when the first shut-off valve 42A and the second shut-off valve 42B of the first safety device 4A and the second safety device 4B are not connected, the first shut-off valve 42A and the second shut-off valve 42B cannot be controlled by the shut-off valve control unit 36. Therefore, when the first shut-off valve 42A and the second shut-off valve 42B are not connected, an interlock may be implemented. Furthermore, valves for opening and closing the first pipe 10A and the second pipe 10B may be provided separately from the first shut-off valve 42A and the second shut-off valve 42B as safety devices, and the opening and closing may be controlled by the shut-off valve control unit 36.

[0056] Embodiment 3. Embodiment 3 will be described. The refrigeration cycle apparatus 100 of embodiment 3 differs from embodiment 1 in the interlock process. The other configurations and functions of the refrigeration cycle apparatus 100 of this embodiment are the same as those of embodiment 1.

[0057] 7 is a flowchart showing the flow of the interlock process in the third embodiment. First, the information acquisition unit 31 acquires the type of refrigerant used in the refrigeration cycle apparatus 100 (S31). Then, the flammability determination unit 32 determines whether the refrigerant used is a non-flammable refrigerant (S32). If the refrigerant used is a non-flammable refrigerant (S32: YES), the connection determination unit 33 determines whether the safety device 4 is connected to the control device 3 (S33).

[0058] If the safety device 4 is not connected (S33: NO), the interlock unit 34 permits operation of the heat source unit 1 (S34). On the other hand, if the safety device 4 is connected (S33: YES), the interlock unit 34 prohibits operation of the heat source unit 1 (S36). The notification unit 35 then notifies the user that the safety device 4 is connected even though it is not required (S37). If the refrigerant used is a non-flammable refrigerant, there is no need to connect the safety device 4. Therefore, if the refrigerant used is a non-flammable refrigerant but the safety device 4 is connected, an interlock is activated and a notification to that effect is issued to the user.

[0059] When the refrigerant used is not a non-flammable refrigerant, that is, when the refrigerant used is a slightly flammable refrigerant or a flammable refrigerant (S32: NO), the processing of steps S35 to S37 is the same as the processing of steps S4 to S6 in the first embodiment.

[0060] As described above, according to this embodiment, as in the first embodiment, if a slightly flammable or flammable refrigerant is mistakenly charged when the safety device 4 is not connected, the heat source unit 1 is not operated, thereby preventing refrigerant leakage and improving safety. Furthermore, if a non-flammable refrigerant is mistakenly charged when the safety device 4 is connected, operation of the heat source unit 1 is prohibited, thereby eliminating the connection of an unnecessary safety device. In other words, if the input refrigerant type information does not match the configuration of the refrigeration cycle apparatus 100, an interlock is activated to notify the user of the mismatch.

[0061] If the refrigerant used is a non-flammable refrigerant and the safety device 4 is connected, there is no problem with safety, and therefore interlocking by the interlock unit 34 is not necessary. In this case, the notification unit 35 notifies the user that the refrigerant used is a non-flammable refrigerant and that the safety device 4 is connected.

[0062] Fourth Embodiment A fourth embodiment will be described. The refrigeration cycle apparatus 100 of the fourth embodiment differs from that of the first embodiment in the interlock process. The other configurations and functions of the refrigeration cycle apparatus 100 of the present embodiment are the same as those of the first embodiment.

[0063] Fig. 8 is a control block diagram of a control device 3B according to embodiment 4. As shown in Fig. 8, the control device 3B has an information acquisition unit 31, a flammability determination unit 32, a connection determination unit 33, an interlock unit 34, a notification unit 35, and a refrigerant amount determination unit 37. The configurations and functions of the flammability determination unit 32 and the connection determination unit 33, as well as the configurations of the information acquisition unit 31, the interlock unit 34, and the notification unit 35, are the same as those in embodiment 1.

[0064] The information acquisition unit 31 acquires the type of refrigerant used in the refrigeration cycle apparatus 100, as well as the amount of refrigerant sealed in the refrigerant circuit of the refrigeration cycle apparatus 100. The amount of refrigerant is input by the user using an external device such as a remote controller of the refrigeration cycle apparatus 100 or a smartphone carried by the user, or an input device connected to the control device 3. The information acquisition unit 31 communicates with the external device or the input device to acquire the amount of refrigerant input by the user.

[0065] When the flammability determination unit 32 determines that the refrigerant used in the refrigeration cycle apparatus 100 is not a non-flammable refrigerant, the refrigerant amount determination unit 37 determines whether the refrigerant amount obtained by the information acquisition unit 31 is equal to or less than a specified amount. The specified amount is, for example, the maximum refrigerant amount for each refrigerant type specified in the JRA standard, or an amount calculated based on an LFL (Lower Flammable Limit) determined from the size of the room in which the heat source unit 1 or the load unit 2 is installed and the type of refrigerant. In this case, the size of the room in which the heat source unit 1 or the load unit 2 is installed is input by the user from an external device or an input device and acquired by the information acquisition unit 31.

[0066] The interlock unit 34 controls the operation of the heat source unit 1 according to the determination result of the connection determination unit 33 regarding the connection of the safety device 4 and the determination result of the refrigerant amount determination unit 37. If the connection determination unit 33 determines that the safety device 4 is not connected, or if the refrigerant amount determination unit 37 determines that the amount of refrigerant is greater than a specified amount, the notification unit 35 issues an alarm or a warning message to that effect.

[0067] 9 is a flowchart showing the flow of the interlock process in the fourth embodiment. In this process, first, the information acquisition unit 31 acquires the type and amount of refrigerant used in the refrigeration cycle apparatus 100 (S41). Then, the flammability determination unit 32 determines whether the refrigerant used is a non-flammable refrigerant (S42). If the refrigerant used is a non-flammable refrigerant (S42: YES), the interlock unit 34 permits operation of the heat source unit 1 (S43).

[0068] On the other hand, if the refrigerant used is not a non-flammable refrigerant, i.e., if the refrigerant used is a slightly flammable refrigerant or a flammable refrigerant (S42: NO), the connection determination unit 33 determines whether the safety device 4 is connected to the refrigeration cycle apparatus 100 (S44). If the safety device 4 is connected (S44: YES), the refrigerant amount determination unit 37 determines whether the refrigerant amount acquired by the information acquisition unit 31 is equal to or less than a specified amount (S45). If the refrigerant amount is equal to or less than the specified amount (S45: YES), the interlock unit 34 permits operation of the heat source unit 1 (S43).

[0069] If the amount of refrigerant is not equal to or less than the specified amount (S45: NO), the interlock unit 34 prohibits operation of the heat source unit 1 (S46). Then, the notification unit 35 notifies that the amount of refrigerant exceeds the specified amount (S47). Also, if the safety device 4 is not connected (S44: NO), the interlock unit 34 also prohibits operation of the heat source unit 1 (S46), and the notification unit 35 notifies that the safety device 4 is not connected (S47). Then, the process returns to step S44, and operation of the heat source unit 1 is prohibited until the safety device 4 is connected and the amount of refrigerant falls below the specified amount.

[0070] As described above, according to this embodiment, if a slightly flammable or flammable refrigerant is accidentally charged when the safety device 4 is not connected, the heat source unit 1 is not operated, thereby preventing refrigerant leakage and improving safety, as in the case of embodiment 1. Furthermore, even if a refrigerant exceeding a specified amount is accidentally charged, the heat source unit 1 is not operated, thereby preventing violation of laws and regulations and improving safety.

[0071] Fifth Embodiment A fifth embodiment will be described. The refrigeration cycle apparatus 100 of the fifth embodiment differs from that of the first embodiment in the interlock process. The other configurations and functions of the refrigeration cycle apparatus 100 of the present embodiment are the same as those of the first embodiment.

[0072] Fig. 10 is a control block diagram of a control device 3C according to embodiment 5. As shown in Fig. 10, the control device 3C has an information acquisition unit 31, a flammability determination unit 32, a connection determination unit 33, an interlock unit 34, a notification unit 35, and a ventilation rate determination unit 38. The configurations and functions of the flammability determination unit 32 and the connection determination unit 33, as well as the configurations of the information acquisition unit 31, the interlock unit 34, and the notification unit 35, are the same as those in embodiment 1.

[0073] The information acquisition unit 31 acquires the type of refrigerant used in the refrigeration cycle apparatus 100, as well as the ventilation rate of the room in which the heat source unit 1 or the load unit 2 is installed. The ventilation rate is input by the user using an external device such as a remote controller of the refrigeration cycle apparatus 100 or a smartphone carried by the user, or an input device connected to the control device 3. The information acquisition unit 31 communicates with the external device or the input device to acquire the ventilation rate input by the user.

[0074] When the flammability determination unit 32 determines that the refrigerant used in the refrigeration cycle apparatus 100 is not a non-flammable refrigerant, the ventilation frequency determination unit 38 determines whether the ventilation frequency obtained by the information acquisition unit 31 is equal to or greater than a specified frequency. The specified frequency is, for example, 0.5 times / h as specified by the Building Standards Act, or a frequency determined from the size of the room in which the heat source unit 1 or the load unit 2 is installed. In this case, the size of the room in which the heat source unit 1 or the load unit 2 is installed is input by the user from an external device or an input device and acquired by the information acquisition unit 31.

[0075] The interlock unit 34 controls the operation of the heat source unit 1 according to the determination result of the connection determination unit 33 regarding the connection of the safety device 4 and the determination result of the ventilation frequency determination unit 38. If the connection determination unit 33 determines that the safety device 4 is not connected, or if the ventilation frequency determination unit 38 determines that the ventilation frequency is less than a specified frequency, the notification unit 35 notifies this fact by issuing an alarm or a warning message.

[0076] 11 is a flowchart showing the flow of the interlock process in the fifth embodiment. In this process, first, the information acquisition unit 31 acquires the type of refrigerant used in the refrigeration cycle apparatus 100 and the ventilation rate (S51). Then, the flammability determination unit 32 determines whether the refrigerant used is a non-flammable refrigerant (S52). If the refrigerant used is a non-flammable refrigerant (S52: YES), the interlock unit 34 permits operation of the heat source unit 1 (S53).

[0077] On the other hand, if the refrigerant used is not a non-flammable refrigerant, i.e., if the refrigerant used is a slightly flammable refrigerant or a flammable refrigerant (S52: NO), the connection determination unit 33 determines whether or not the safety device 4 is connected to the refrigeration cycle apparatus 100 (S54). If the safety device 4 is connected (S54: YES), the ventilation frequency determination unit 38 determines whether or not the ventilation frequency acquired by the information acquisition unit 31 is equal to or greater than a specified frequency (S55). If the ventilation frequency is equal to or greater than the specified frequency (S55: YES), the interlock unit 34 permits operation of the heat source unit 1 (S53).

[0078] If the ventilation frequency is less than the specified frequency (S55: NO), the interlock unit 34 prohibits operation of the heat source unit 1 (S56). Then, the notification unit 35 notifies the user that the ventilation frequency is less than the specified frequency (S57). Also, if the safety device 4 is not connected (S54: NO), the interlock unit 34 also prohibits operation of the heat source unit 1 (S56), and the notification unit 35 notifies the user that the safety device 4 is not connected (S57). Then, the process returns to step S54, and operation of the heat source unit 1 is prohibited until the safety device 4 is connected and the ventilation frequency reaches or exceeds the specified frequency.

[0079] As described above, according to this embodiment, if a slightly flammable or flammable refrigerant is accidentally charged when the safety device 4 is not connected, the heat source unit 1 is not operated, thereby preventing refrigerant leakage and improving safety, as in the case of embodiment 1. Furthermore, if the ventilation rate is accidentally set below a specified rate, the heat source unit 1 is not operated, thereby preventing violation of laws and regulations and improving safety.

[0080] In the fifth embodiment, the information acquisition unit 31 may acquire the installation location of the load unit 2 input by the user to an external device or an input device. In this case, the control device 3C may perform an interlock based on the ventilation rate only when the acquired installation location is a semi-basement or a machine room.

[0081] The above is a description of the embodiments, but the present disclosure is not limited to the above embodiments and can be modified in various ways without departing from the spirit of the present disclosure. Furthermore, the present disclosure includes all possible combinations of the configurations shown in the above embodiments. For example, embodiments 1 to 5 can be combined as appropriate. For example, embodiment 2 or 3 may be combined with embodiment 4 for determining the refrigerant amount or embodiment 5 for determining the ventilation rate.

[0082] In the above embodiment, the connection determination unit 33 determines whether the safety device 4 is connected based on a predetermined criterion. However, the connection determination unit 33 may set the criterion based on input from a user. Specifically, when the interlock process is started, the user inputs, via an external device or input device, usage conditions including the type of refrigerant used in the refrigeration cycle apparatus 100 as well as at least one of applicable laws and regulations, the amount of refrigerant sealed in the refrigerant circuit, and the size of the space in which the heat source unit 1 or the load unit 2 is installed, and the input conditions are acquired by the information acquisition unit 31. If the refrigerant used is not a non-flammable refrigerant, i.e., if the refrigerant used is a slightly flammable refrigerant or a flammable refrigerant (S2: NO), the connection determination unit 33 determines the safety device 4 required for the refrigeration cycle apparatus 100 based on the usage conditions input by the user.

[0083] Specifically, the connection determination unit 33 determines, based on the usage conditions, which of the refrigerant leak detection device 41, the shutoff valve 42, the alarm device 43, and the ventilation device 44 devices that need to be connected as the safety device 4, and the number of such devices. Then, when the determined device is connected, the connection determination unit 33 determines that the safety device 4 is connected. This makes it possible to automatically determine the presence or absence of the safety device 4 according to the actual usage conditions of the refrigeration cycle apparatus 100, such as laws and regulations, the type of refrigerant used, the amount of refrigerant sealed in the refrigerant circuit, and the size of the space.

[0084] Furthermore, when the refrigeration cycle apparatus 100 is a refrigerator, the heat source unit 1 and the load unit 2 (cooler) may be made by different manufacturers. In such a case, if the safety device 4 is not connected, even if a signal indicating that the safety device 4 is not connected is sent from a remote controller or the like connected to the load unit 2 to the heat source unit 1, the heat source unit 1 may not receive the signal. Conversely, even if the heat source unit 1 sends a signal indicating that the safety device 4 is not connected to the load unit 2, the load unit 2 may not receive the signal. Therefore, when the heat source unit 1 and the load unit 2 are made by different manufacturers, a manual or the like may be used to warn the user to check the safety device 4, and the interlock in the interlock unit 34 may not function even if the safety device 4 is not connected. In this case, information regarding the manufacturers of the heat source unit 1 and the load unit 2 is input by the user via an external device or input device and acquired by the information acquisition unit 31.

[0085] 1 Heat source unit, 2 Load unit, 2A First load unit, 2B Second load unit, 3, 3A, 3B, 3C Control device, 4 Safety device, 4A First safety device, 4B Second safety device, 10 Piping, 10A First piping, 10B Second piping, 31 Information acquisition unit, 32 Flammability determination unit, 33 Connection determination unit, 34 Interlock unit, 35 Alarm unit, 36 Shut-off valve control unit, 37 Refrigerant amount determination unit, 38 Ventilation frequency determination unit, 41 Refrigerant leak detection device, 41A First refrigerant leak detection device, 41B Second refrigerant leak detection device, 42 Shut-off valve, 42A First shut-off valve, 42B Second shut-off valve, 43 Alarm device, 43A First alarm device, 43B Second alarm device, 44 Ventilation device, 44A First ventilation device, 44B Second ventilation device, 100, 100A Refrigeration cycle device.

Claims

1. A refrigeration cycle apparatus comprising: a heat source unit constituting at least a part of a refrigerant circuit; a load unit connected to the heat source unit; and a control device controlling the heat source unit, wherein the control device has: an information acquisition unit that acquires the type of refrigerant used in the refrigerant circuit; a connection determination unit that determines whether a safety device is connected if the type of refrigerant acquired by the information acquisition unit is not a non-flammable refrigerant; and an interlock unit that prohibits operation of the heat source unit if the connection determination unit determines that the safety device is not connected.

2. The refrigeration cycle apparatus according to claim 1, wherein the safety device is at least one of a refrigerant leakage detection device, a shutoff valve, an alarm device, and a ventilation device.

3. The refrigeration cycle device of claim 2, wherein the information acquisition unit acquires usage conditions including at least any of applicable laws or regulations, the type of refrigerant, the amount of refrigerant sealed in the refrigerant circuit, and the size of the space in which the heat source unit or the load unit is installed, and the connection determination unit determines, based on the usage conditions, which of the refrigerant leakage detection device, the shut-off valve, the alarm device, and the ventilation device will be connected as the safety device, and determines whether the determined device is connected.

4. A refrigeration cycle device as described in any one of claims 1 to 3, wherein the control device further has an alarm unit that notifies the user that the safety device is not connected when the connection determination unit determines that the safety device is not connected.

5. A refrigeration cycle device as described in any one of claims 1 to 4, wherein the load units include a first load unit and a second load unit, and the connection determination unit determines whether a first safety device corresponding to the first load unit and a second safety device corresponding to the second load unit are connected, respectively, when the type of refrigerant acquired by the information acquisition unit is not a non-flammable refrigerant, and the interlock unit prohibits operation of the heat source unit when the connection determination unit determines that both the first safety device and the second safety device are not connected, and allows operation of the heat source unit when the connection determination unit determines that at least one of the first safety device and the second safety device is connected.

6. A refrigeration cycle apparatus as described in claim 5, further comprising: a first shut-off valve provided in a first pipe connecting the heat source unit and the first load unit; and a second shut-off valve provided in a second pipe connecting the heat source unit and the second load unit, wherein the control device further comprises a shut-off valve control section that, when the connection determination section determines that the first safety device is not connected, closes the first shut-off valve to shut off the flow of refrigerant from the heat source unit to the first load unit, and when the connection determination section determines that the second safety device is not connected, closes the second shut-off valve to shut off the flow of refrigerant from the heat source unit to the second load unit.

7. A refrigeration cycle device as described in any one of claims 4 to 6, wherein the connection determination unit determines whether or not the safety device is connected when the type of refrigerant obtained by the information acquisition unit is a non-flammable refrigerant, and when the type of refrigerant obtained by the information acquisition unit is a non-flammable refrigerant and the connection determination unit determines that the safety device is connected, the interlock unit prohibits operation of the heat source unit, or the notification unit notifies that the type of refrigerant is a non-flammable refrigerant and that the safety device is connected.

8. A refrigeration cycle device as described in any one of claims 1 to 7, wherein the information acquisition unit acquires a refrigerant amount, which is the amount of refrigerant sealed in the refrigerant circuit, and the interlock unit prohibits operation of the heat source unit if the refrigerant amount acquired by the information acquisition unit is greater than a specified amount.

9. A refrigeration cycle device as described in any one of claims 1 to 8, wherein the information acquisition unit acquires the ventilation rate of the space in which the heat source unit or the load unit is installed, and the interlock unit prohibits operation of the heat source unit if the ventilation rate acquired by the information acquisition unit is less than a specified rate.

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